[atlas] Bug when creating DNS6 with udp_reply_bytes via API

Hi RIPE Atlas developers,

I found a bug in the DNS API.

When creating a DNS measurements via the API that have udp_reply_bytes
property set, they never leave the "Scheduled" state and eventually fail.

When I query the status of the measurements I notice that they have the
udp_payload_size property set to true in stead of the value given with
udp_reply_bytes. This is different from measurements created via the
interface, where udp_payload_size reflects udp_reply_bytes.

Also, it appears I can only origin 80 probes (by probe id), whilst in
the interface I can origin from 500 probes. Is that correct? Would it be
possible to (temporarily) increase my limit to 1050 probes?

Best regards,

-- Willem